Temperature evaluations using water temperature and humidity sensor in a washing machine

ABSTRACT

A laundry appliance includes a tub, a drum rotatably mounted within the tub and defining a chamber configured for receiving a load of clothes, a water temperature sensor in the tub, and a humidity sensor having an air temperature sensor in an exhaust in fluid communication with the chamber. A controller is configured to take a series of readings from the water temperature sensor and the air temperature sensor, to determine a difference or average of the temperature changes in those sensors, and to compare the rate of temperature change over time. Where the controller determines that the rate of change between the water temperature sensor and the air temperature sensor is inconsistent, the controller provides a notification to the user that one or both of the temperature sensors is in error and requires servicing.

FIELD OF THE INVENTION

The present subject matter relates generally to evaluating temperaturesin laundry appliances, or more specifically, to determining if atemperature sensor in the laundry appliance is providing erroneousreadings, thereby necessitating service.

BACKGROUND OF THE INVENTION

Washing machine appliances generally include a tub for containing wateror wash fluid, e.g., water and detergent, bleach, and/or other washadditives. A drum is rotatably mounted within the tub and defines a washchamber for receipt of articles for washing. During normal operation ofsuch washing machine appliances, the wash fluid is directed into the tuband onto articles within the wash chamber of the drum. The drum or anagitation element can rotate at various speeds to agitate articleswithin the wash chamber, to wring wash fluid from articles within thewash chamber, etc. During a spin or drain cycle of a washing machineappliance, a drain pump assembly may operate to discharge water fromwithin sump.

For many types of wash cycles, the temperature of the water may play animportant role in cleaning of the articles for washing. The temperatureis determined via a thermistor within the tub that directly measures thewater temperature therein. Failure of the thermistor to properly readthe water temperature will inhibit that ability of the washing machineappliance to carry out heated wash cycles effectively.

Conventional washing machine appliances attempt to address the problemby assessing whether the temperature significantly exceeds or fallsshort of expected normal operating temperatures. This approach workswell when the thermistor has completely failed but is ineffective wherea thermistor is malfunctioning but still provides a reading withinexpected thresholds. Even in this circumstance, however, washingperformance may be significantly hampered by the misreading.

Accordingly, a laundry appliance including features and operatingmethods for monitoring for temperature sensor malfunctions is desirable.More specifically, it would be desirable to determine if a temperaturesensor's reading is accurate or whether replacement of the temperaturesensor is necessary.

BRIEF DESCRIPTION OF THE INVENTION

Advantages of the invention will be set forth in part in the followingdescription, or may be apparent from the description, or may be learnedthrough practice of the invention.

In one exemplary embodiment, a laundry appliance is provided including acabinet, a tub within the cabinet, a drum rotatably mounted within thetub and defining a chamber, an exhaust in fluid communication with thechamber, a first temperature sensor, a second temperature sensor, and acontroller operably coupled to the first temperature sensor and thesecond temperature sensor. The controller may be configured to execute awash cycle, receive a first temperature of the first temperature sensor,receive a first temperature of the second temperature sensor, receive asecond temperature of the first temperature sensor, receive a secondtemperature of the second temperature sensor, determine the temperaturechange of the first temperature sensor and the second temperature sensorbased at least in part on the first temperature and the secondtemperature of the first temperature sensor and the second temperaturesensor, compare the temperature change of the first temperature sensorto the temperature change of the second temperature sensor, anddetermine if either of the first temperature sensor or the secondtemperature sensor are malfunctioning based on the comparison.

In another exemplary embodiment, a method is provided of monitoring fortemperature sensor malfunction in a laundry appliance having a cabinet,a tub within the cabinet, a drum rotatably mounted within the tub anddefining a chamber, an exhaust in fluid communication with the chamber,a first temperature sensor in the tub for measuring water temperature,and a second temperature sensor in a humidity sensor disposed in theexhaust for measuring air temperature. The method may comprise the stepsof executing a wash cycle, receiving a first temperature of the firsttemperature sensor, receiving a first temperature of the secondtemperature sensor, receiving a second temperature of the firsttemperature sensor, receiving a second temperature of the secondtemperature sensor, determining the temperature change of the firsttemperature sensor and the second temperature sensor based at least inpart on the first temperature and the second temperature of the firsttemperature sensor and the second temperature sensor, comparing thetemperature change of the first temperature sensor to the temperaturechange of the second temperature sensor, and determining if either ofthe first temperature sensor or the second temperature sensor aremalfunctioning based on the comparison.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures.

FIG. 1 provides a perspective view of an exemplary washing machineappliance according to an exemplary embodiment of the present subjectmatter.

FIG. 2 provides a side cross-sectional view of the exemplary washingmachine appliance of FIG. 1 .

FIG. 3 provides a perspective view of a fan and humidity sensor within awashing machine appliance according to an exemplary embodiment of thepresent subject matter.

FIG. 4 provides a graph of temperature over time for a functioning airtemperature sensor and a functioning water temperature sensor accordingto an exemplary embodiment of the present subject matter.

FIG. 5 provides a flow diagram illustrating a portion of an exemplaryprocess for monitoring for temperature sensor malfunctions according toan exemplary embodiment of the present subject matter.

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features orelements of the present invention.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

As used herein, the terms “first,” “second,” and “third” may be usedinterchangeably to distinguish one component from another and are notintended to signify location or importance of the individual components.The terms “includes” and “including” are intended to be inclusive in amanner similar to the term “comprising.” Similarly, the term “or” isgenerally intended to be inclusive (i.e., “A or B” is intended to mean“A or B or both”). Approximating language, as used herein throughout thespecification and claims, is applied to modify any quantitativerepresentation that could permissibly vary without resulting in a changein the basic function to which it is related. Accordingly, a valuemodified by a term or terms, such as “about,” “approximately,” and“substantially,” are not to be limited to the precise value specified.In at least some instances, the approximating language may correspond tothe precision of an instrument for measuring the value. For example, theapproximating language may refer to being within a 10 percent margin.

Referring now to the figures, an exemplary laundry appliance that may beused to implement aspects of the present subject matter will bedescribed. Specifically, FIG. 1 is a perspective view of an exemplaryhorizontal axis washing machine appliance 100 and FIG. 2 is a sidecross-sectional view of washing machine appliance 100. As illustrated,washing machine appliance 100 generally defines a vertical direction V,a lateral direction L, and a transverse direction T, each of which ismutually perpendicular, such that an orthogonal coordinate system isgenerally defined. Washing machine appliance 100 includes a cabinet 102that extends between a top 104 and a bottom 106 along the verticaldirection V, between a left side 108 and a right side 110 along thelateral direction, and between a front 112 and a rear 114 along thetransverse direction T (FIG. 2 ).

Referring to FIG. 2 , a drum 120 is rotatably mounted within cabinet 102such that it is rotatable about an axis of rotation A. A motor 122,e.g., such as a pancake motor, is in mechanical communication with drum120 to selectively rotate drum 120 (e.g., during an agitation or a rinsecycle of washing machine appliance 100). Drum 120 is received within awash tub 124 and defines a wash chamber 126 that is configured forreceipt of articles for washing. The wash tub 124 holds wash and rinsefluids for agitation in drum 120 within wash tub 124. As used herein,“wash fluid” may refer to water, detergent, fabric softener, bleach, orany other suitable wash additive or combination thereof. Indeed, forsimplicity of discussion, these terms may all be used interchangeablyherein without limiting the present subject matter to any particular“wash fluid.”

Drum 120 may define one or more agitator features that extend into washchamber 126 to assist in agitation and cleaning articles disposed withinwash chamber 126 during operation of washing machine appliance 100. Forexample, as illustrated in FIG. 2 , a plurality of ribs 128 extends frombasket 120 into wash chamber 126. In this manner, for example, ribs 128may lift articles disposed in drum 120 during rotation of drum 120.

Referring generally to FIGS. 1 and 2 , cabinet 102 also includes a frontpanel 130 which defines an opening 132 that permits user access to drum120 of wash tub 124. More specifically, washing machine appliance 100includes a door 134 that is positioned over opening 132 and is rotatablymounted to front panel 130. In this manner, door 134 permits selectiveaccess to opening 132 by being movable between an open position (notshown) facilitating access to a wash tub 124 and a closed position (FIG.1 ) prohibiting access to wash tub 124.

A window 136 in door 134 permits viewing of drum 120 when door 134 is inthe closed position, e.g., during operation of washing machine appliance100. Door 134 also includes a handle (not shown) that, e.g., a user maypull when opening and closing door 134. Further, although door 134 isillustrated as mounted to front panel 130, it should be appreciated thatdoor 134 may be mounted to another side of cabinet 102 or any othersuitable support according to alternative embodiments. Washing machineappliance 100 may further include a latch assembly 138 (see FIG. 1 )that is mounted to cabinet 102 and/or door 134 for selectively lockingdoor 134 in the closed position and/or confirming that the door is inthe closed position. Latch assembly 138 may be desirable, for example,to ensure only secured access to wash chamber 126 or to otherwise ensureand verify that door 134 is closed during certain operating cycles orevents.

Referring again to FIG. 2 , drum 120 also defines a plurality ofperforations 140 in order to facilitate fluid communication between aninterior of drum 120 and wash tub 124. A sump 142 is defined by wash tub124 at a bottom of wash tub 124 along the vertical direction V. Thus,sump 142 is configured for receipt of and generally collects wash fluidduring operation of washing machine appliance 100. For example, duringoperation of washing machine appliance 100, wash fluid may be urged bygravity from drum 120 to sump 142 through plurality of perforations 140.

A drain pump assembly 144 is located beneath wash tub 124 and is influid communication with sump 142 for periodically discharging soiledwash fluid from washing machine appliance 100. Drain pump assembly 144may generally include a drain pump 146 which is in fluid communicationwith sump 142 and with an external drain 148 through a drain hose 150.During a drain cycle, drain pump 146 urges a flow of wash fluid fromsump 142, through drain hose 150, and to external drain 148. Morespecifically, drain pump 146 includes a motor (not shown) which isenergized during a drain cycle such that drain pump 146 draws wash fluidfrom sump 142 and urges it through drain hose 150 to external drain 148.

A spout 152 is configured for directing a flow of fluid into wash tub124. For example, spout 152 may be in fluid communication with a watersupply 154 (FIG. 2 ) in order to direct fluid (e.g., clean water or washfluid) into wash tub 124. Spout 152 may also be in fluid communicationwith the sump 142. For example, pump assembly 144 may direct wash fluiddisposed in sump 142 to spout 152 in order to circulate wash fluid inwash tub 124.

As illustrated in FIG. 2 , a detergent drawer 156 is slidably mountedwithin front panel 130. Detergent drawer 156 receives a wash additive(e.g., detergent, fabric softener, bleach, or any other suitable liquidor powder) and directs the fluid additive to wash tub 124 duringoperation of washing machine appliance 100. According to the illustratedembodiment, detergent drawer 156 may also be fluidly coupled to spout152 to facilitate the complete and accurate dispensing of wash additive.It should be appreciated that according to alternative embodiments,these wash additives could be dispensed automatically via a bulkdispensing unit (not shown). Other systems and methods for providingwash additives are possible and within the scope of the present subjectmatter.

In addition, a water supply valve 158 may provide a flow of water from awater supply source (such as a municipal water supply 154) intodetergent dispenser 156 and into wash tub 124. In this manner, watersupply valve 158 may generally be operable to supply water intodetergent dispenser 156 to generate a wash fluid, e.g., for use in awash cycle, or a flow of fresh water, e.g., for a rinse cycle. It shouldbe appreciated that water supply valve 158 may be positioned at anyother suitable location within cabinet 102. In addition, although watersupply valve 158 is described herein as regulating the flow of “washfluid,” it should be appreciated that this term includes, water,detergent, other additives, or some mixture thereof.

Referring again to FIG. 1 , control panel 160 including a plurality ofinput selectors 162 is coupled to front panel 130. Control panel 160 andinput selectors 162 collectively form a user interface input foroperator selection of machine cycles and features. For example, in oneembodiment, a display 164 indicates selected features, a countdowntimer, and/or other items of interest to machine users. Operation ofwashing machine appliance 100 is controlled by a controller orprocessing device 166 that is operatively coupled to control panel 160for user manipulation to select washing machine cycles and features. Inresponse to user manipulation of control panel 160, controller 166operates the various components of washing machine appliance 100 toexecute selected machine cycles and features.

Controller 166 may include a memory and microprocessor, such as ageneral or special purpose microprocessor operable to executeprogramming instructions or micro-control code associated with acleaning cycle. The memory may represent random access memory such asDRAM, or read only memory such as ROM or FLASH. In one embodiment, theprocessor executes programming instructions stored in memory. The memorymay be a separate component from the processor or may be includedonboard within the processor. Alternatively, controller 166 may beconstructed without using a microprocessor, e.g., using a combination ofdiscrete analog and/or digital logic circuitry (such as switches,amplifiers, integrators, comparators, flip-flops, AND gates, and thelike) to perform control functionality instead of relying upon software.Control panel 160 and other components of washing machine appliance 100may be in communication with controller 166 via one or more signal linesor shared communication busses.

During operation of washing machine appliance 100, laundry items areloaded into drum 120 through opening 132, and washing operation isinitiated through operator manipulation of input selectors 162. Wash tub124 is filled with water, detergent, and/or other fluid additives, e.g.,via spout 152 and/or detergent drawer 156. One or more valves (e.g.,water supply valve 158) can be controlled by washing machine appliance100 to provide for filling drum 120 to the appropriate level for theamount of articles being washed and/or rinsed. By way of example for awash mode, once drum 120 is properly filled with fluid, the contents ofdrum 120 can be agitated (e.g., with ribs 128) for washing of laundryitems in drum 120.

After the agitation phase of the wash cycle is completed, wash tub 124can be drained. Laundry articles can then be rinsed by again addingfluid to wash tub 124, depending on the particulars of the cleaningcycle selected by a user. Ribs 128 may again provide agitation withindrum 120. One or more spin cycles may also be used. In particular, aspin cycle may be applied after the wash cycle and/or after the rinsecycle in order to wring wash fluid from the articles being washed.During a final spin cycle, drum 120 is rotated at relatively high speedsand drain assembly 144 may discharge wash fluid from sump 142. Afterarticles disposed in drum 120 are cleaned, washed, and/or rinsed, theuser can remove the articles from drum 120, e.g., by opening door 134and reaching into drum 120 through opening 132.

Notably, controller 166 of washing machine appliance 100 (or any othersuitable dedicated controller) may be communicatively coupled to controlpanel 160 and input selectors 162, and other components of washingmachine appliance 100, such as fan 204, humidity sensor 202, firsttemperature sensor 216, and second temperature sensor 218 as describedbelow. As explained in more detail below, controller 166 may beprogrammed or configured for automating elements of the washing machineappliance 100 at particular times as part of particular cycles, e.g.,such as initiating an automated drying cycle upon completion of aself-cleaning cycle with little or no user intervention.

Referring still to FIG. 1 , a schematic diagram of an externalcommunication system 190 will be described according to an exemplaryembodiment of the present subject matter. In general, externalcommunication system 190 is configured for permitting interaction, datatransfer, and other communications with washing machine appliance 100.For example, this communication may be used to provide and receiveoperating parameters, cycle settings, performance characteristics, userpreferences, user notifications, or any other suitable information forimproved performance of washing machine appliance 100.

External communication system 190 permits controller 166 of washingmachine appliance 100 to communicate with external devices eitherdirectly or through a network 192. For example, a consumer may use aconsumer device 194 to communicate directly with washing machineappliance 100. For example, consumer devices 194 may be in direct orindirect communication with washing machine appliance 100, e.g.,directly through a local area network (LAN), Wi-Fi, Bluetooth, Zigbee,etc. or indirectly through network 192. In general, consumer device 194may be any suitable device for providing and/or receiving communicationsor commands from a user. In this regard, consumer device 194 mayinclude, for example, a personal phone, a tablet, a laptop computer, oranother mobile device.

In addition, a remote server 196 may be in communication with washingmachine appliance 100 and/or consumer device 194 through network 192. Inthis regard, for example, remote server 196 may be a cloud-based server196, and is thus located at a distant location, such as in a separatestate, country, etc. In general, communication between the remote server196 and the client devices may be carried via a network interface usingany type of wireless connection, using a variety of communicationprotocols (e.g. TCP/IP, HTTP, SMTP, FTP), encodings or formats (e.g.HTML, XML), and/or protection schemes (e.g. VPN, secure HTTP, SSL).

In general, network 192 can be any type of communication network. Forexample, network 192 can include one or more of a wireless network, awired network, a personal area network, a local area network, a widearea network, the internet, a cellular network, etc. According to anexemplary embodiment, consumer device 194 may communicate with a remoteserver 196 over network 192, such as the internet, to provide userinputs, transfer operating parameters or performance characteristics,receive user notifications or instructions, etc. In addition, consumerdevice 194 and remote server 196 may communicate with washing machineappliance 100 to communicate similar information.

External communication system 190 is described herein according to anexemplary embodiment of the present subject matter. However, it shouldbe appreciated that the exemplary functions and configurations ofexternal communication system 190 provided herein are used only asexamples to facilitate description of aspects of the present subjectmatter. System configurations may vary, other communication devices maybe used to communicate directly or indirectly with one or more laundryappliances, other communication protocols and steps may be implemented,etc. These variations and modifications are contemplated as within thescope of the present subject matter.

Referring again to the embodiment of FIG. 1 , door 134 may furtherinclude air intake openings 206. Air intake openings 206 may be one ormore openings in door 134 that permit air to pass between the outsideand the inside of wash tub 124. To enable this function, air intakeopenings 206 may be located on both the interior and exterior surfacesof door 134. In some embodiments, air intake openings 206 may constitutenumerous small, individual openings. In alternative embodiments, airintake openings 206 may constitute only a single opening. The surfacearea of the air intake openings 206 (or the combined surface area in thecase of multiple air intake openings 206) may be varied to control, inpart, the flow of air between the exterior and interior of the tub. Insome embodiments, it may be desirable to include a screen or otherfilter (not pictured) over the air intake openings to discourage thepassage of lint or other solids from entering the wash tub 124. Althoughair intake openings 206 are located in door 134 in the embodiment ofFIG. 1 , it will be recognized that air intake openings 206 may belocated elsewhere on washing machine appliance 100 in alternativeembodiments. Indeed, air intake openings 206 may be located anywherethat would allow passage of air between the inside and the outside ofwash tub 124, such as on a surface of cabinet 130.

As shown in FIG. 1 , washing machine appliance 100 may further include adamper 208. In the embodiment of FIG. 1 , damper 208 may include a firstend 210 and a second end 212. A damper opening 214 may be located at thesecond end 212 of damper 208. Damper 208 may be movable between an openand closed position, wherein the open position is characterized byalignment of damper opening 214 with air intake openings 206 and theclosed position is characterized by alignment of the first end 210 ofdamper 208 with air intake openings 206. When in the closed position,damper 208 blocks the passage of air between the inside and the outsideof wash tub 124. Conversely, in the open position, damper 208 permitssuch air flow. Although a particular embodiment of damper 208 isprovided in FIG. 1 , it will be recognized that other embodiments forselectively permitting air flow into the wash tub 124 through air intakeopenings 206 fall within the scope of the present disclosure. Forexample, in some embodiments, damper 208 may lack a damper opening 214altogether. In such an embodiment, the open position of damper 208 ischaracterized by no portion of damper 208 being position in alignmentwith air intake openings 206. In still other embodiments, damper opening214 may consist of a plurality of openings corresponding to theplurality air intake openings 206. In such embodiment, opening orclosing of damper 208 need not involve movement from a first end 210 toa second end 212 (or vice versa), but rather shifting of the alignmentof the plurality of damper openings 214 with the plurality of air intakeopenings 206. In still other embodiments, damper 208 may consist of aseries of planar elements aligned with the air intake openings 206 thatindividually rotate about a vertical axis, the rotation resulting incovering and uncovering the air intake openings 206. Those of ordinaryskill will recognize that other embodiments of a moving damper thatselectively allow air flow through the air intake openings 206 areintended to fall within the scope of the present disclosure.

Referring now to FIG. 3 , washing machine appliance 100 further includesan exhaust 200. Exhaust 200 couples tub 124 to the exterior of cabinet102, proving a path to exhaust air from tub 124 and chamber 126. Exhaust200 further includes a fan 204, a conduit 205, and humidity sensor 202.Fan 204 may be positioned on the rear 114 of cabinet 102. Fan 204 may beattached to conduit 205. Conduit 205 may be further attached to wash tub124. Fan 204 operates by drawing air out of wash tub 124, throughconduit 205, and exhausting the air from washing machine appliance 100.Washing machine appliance may further include a humidity sensor 202 formeasuring the humidity of the air being exhausted from wash tub 124. Asshown in FIG. 3 , fan 204 is situated along the rear 114 of cabinet 102and humidity sensor 202 is situated in close proximity to fan 204.However, in alternative embodiments, fan 204 and humidity sensor 202 maybe located in alternative locations, so long as fan 204 serves to drawair from wash tub 124 and exhaust it from washing machine appliance 100,and humidity sensor 202 is positioned to read the humidity level of thisexhausted air.

Washing machine appliance 100 may further include a first temperaturesensor 216 (FIG. 2 ). First temperature sensor 216 may, in someembodiments, be situated at least partially within tub 124. Preferably,in these embodiments, first temperature sensor may be situated near abottom of tub 124 to aid in measuring the temperature of water withintub 124 even when the water volume is low. In alternative embodiments,first temperature sensor 216 may be located at a water inlet to tub 124.Alternative locations are possible and are intended to fall within thescope of the present disclosure, though its location should bedownstream of the point where hot and cold water are mixed. Firsttemperature sensor 216, in one embodiment, measures water temperature.The temperature reading of first temperature sensor 216 may be used, forexample, to control the flow of hot water, cold water, or both to alterthe temperature of water used in a given cycle.

Washing machine appliance 100 may further include a second temperaturesensor 218 (FIG. 3 ). In some embodiments, temperature sensor 218 may besituated within exhaust 200 and may measure the temperature of airexhausted from tub 124. Second temperature sensor 218 may be an elementof humidity sensor 202, in some embodiments, or may be a separate andindependent from humidity sensor 202 in alternative embodiments. Wherehumidity sensor 202 measures relative humidity (i.e., a measurement ofwater vapor in the air relative to the temperature), it is common forthe humidity sensor 202 to include a temperature sensor which may beused as second temperature sensor 218. In alternative embodiments,second temperature sensor 218 may also measure water temperature and maybe situated with tub 124 or at such other location downstream of theintroduction of hot and cold water.

Referring now to FIG. 4 , the initiation of a wash cycle may begin aprocess of taking readings from first temperature sensor 216 and secondtemperature sensor 218. FIG. 4 provides a graph of such temperaturereadings over time in an embodiment including first temperature sensor216 measuring the temperature of water within tub 124 (lower graph line)and second temperature sensor 218 measuring air temperature withinexhaust 200 (upper graph line) of washing machine appliance 200. Asshown, although the temperature of the exhaust air is substantiallyhigher than the temperature of the water measured, the temperaturestrends are consistent with one another insofar as a rise in the watertemperature is reflected in a rise in air temperature at the exhaust. Asa result, by measuring the temperature of both and comparing theresults, it can be determined whether one of the first temperaturesensor 216 and second temperature sensor 218 has malfunctioned (i.e.,one registers a temperature change over time and the other does not).

While described in the context of a specific embodiment of horizontalaxis washing machine appliance 100, using the teachings disclosed hereinit will be understood that horizontal axis washing machine appliance 100is provided by way of example only. Other washing machine applianceshaving different configurations, different appearances, and/or differentfeatures may also be utilized with the present subject matter as well,e.g., a combination washer/dryer appliance.

Now that the construction of washing machine appliance 100 and theconfiguration of controller 166 according to exemplary embodiments havebeen presented, an exemplary method 300 of operating a washing machineappliance will be described. Referring now to FIG. 5 , method 300includes, at step 310, commencing a washing cycle. During the course ofthe wash cycle, controller 166 receives a series of temperature readingsfrom the first temperature sensor 216 and the second temperature sensor218. In particular, method 300 requires at least receiving a firsttemperature from the first temperature sensor 216 (step 320), a firsttemperature from the second temperature sensor 218 (step 330), a secondtemperature from the first temperature sensor 216 (step 340), and asecond temperature from the second temperature sensor 218 (step 350).

This temperature data is used by controller 166 to determine atemperature change associated with the first temperature sensor 216 anda temperature change associated with the second temperature sensor 218at step 360. This temperature change is based at least in part on thefirst temperature and the second temperature of the first temperaturesensor 216 and the second temperature sensor 218 at steps 320 through350. It will be understood that the temperature change is not limited tothese data points, however. For example, in certain embodiments,controller 166 may receive a plurality of temperature readings over timefrom first temperature sensor 216 and second temperature sensor 218. Inthis scenario, the temperature change determined by controller 166 maybe an average change of temperature associated with first temperaturesensor 216 and second temperature sensor 218 over a fixed period oftime, for example. In alternative embodiments, the temperature changemay reflect the absolute differences between the first temperaturereading and the most recent temperature reading in each of the firsttemperature sensor 216 and the second temperature sensor 218. Othertechniques for determining the change of temperatures will be apparentto those skilled in the art and are intended to fall within the scope ofthe present subject matter.

At step 370 of method 300, the temperature change associated with thefirst temperature sensor 216 is compared to the temperature changeassociated with the second temperature sensor 218 and controller 166determines if either of the first temperature sensor or the secondtemperature sensor are malfunctioning. In comparing the temperaturechange associated with the first temperature sensor 216 with thetemperature change associated with the second temperature sensor 218, itwill be understood that the temperature changes are based onmeasurements using like techniques. For example, in embodiments where aplurality of temperature readings from first temperature sensor 216 andtemperature sensor 218 are received and averaged, the controller 166will compare the average temperature change associated with firsttemperature sensor 216 to the average temperature change associated withsecond temperature sensor 218. Alternatively, where an absolutedifference is determined at step 360, the comparison will be betweenthose absolute differences in temperature change.

In determining if either of the first temperature sensor 216 or secondtemperature sensor 218 are malfunctioning, controller 166 determineswhether the temperature change of the first temperature sensor isconsistent with the temperature change of the second temperature sensor.As used herein, consistency of the temperature changes is not intendedto require precise equality between the temperature changes associatedwith first temperature sensor 216 and second temperature sensor 218.Rather, consistency is intended to be measured by the temperature trendof the temperature change.

For example, in a hot wash cycle, it would be expected for the watertemperature and air temperatures to rise during the course of the washcycle. If both the first temperature sensor 216 and the secondtemperature sensor 218 are working properly, both will reflect this risein temperature. However, the air temperature will be a function of thewater temperature and will necessarily lag behind. Thus, even in aperfectly operating laundry appliance, the second temperature sensor 218may not reflect a temperature rise over exactly the same time frame thatthe first temperature sensor 216 registers a rise in temperature. Norwill the temperature rises be identical due to a variety of factors,including at least heat absorption by articles of laundry and otherportions of the appliance and due to the imprecision of the temperaturesensors themselves. Thus, the term consistency, as used herein, may beattained if the first temperature sensor 216 and the second temperaturesensor 218 both register an increase in temperature over an extendedperiod of time (e.g., 180 seconds). Consistency would likewise beachieved if both sensors registered a decrease or both registered amaintaining of temperature over time. By contrast, the temperaturechanges associated with first temperature sensor 216 and secondtemperature sensor 218 would be inconsistent if the temperature changeof one of the first temperature sensor 216 or the second temperaturesensor 218 has a temperature change over the extended period of time andthe other does not.

If it is determined at step 370 that the temperature changes of firsttemperature sensor 216 and second temperature sensor 218 are consistent,the wash cycle simply continues, as shown at step 380. However, if it isdetermined at step 370 that the temperature changes of first temperaturesensor 216 and second temperature sensor 218 are inconsistent, this isan indication that one or both of first temperature sensor 216 andsecond temperature sensor 218 are malfunction. Continued use of thewashing machine appliance 100 may therefore lead to less effectivewashing cycles and a poor perception of the appliance itself.Accordingly, in the case of inconsistent temperature changes, anotification may be provided to the user that first temperature sensor216 or second temperature sensor 218 are faulty, or that service isotherwise required. This notification may take the form of a light orother signal on control panel 160 or display 164 in certain embodiments.In alternative embodiments, the notification may take the form of anindication sent to consumer device 164. In still other embodiments, thefault may be relayed to a remote server 196, which may result in amessage being delivered to the user. Alternatively, combinations of theabove forms of notification may be employed. Regardless of the form ofnotification, the wash cycle may continue, as the fault does not presenta safety issue.

It will be understood that method 300 may further include repeatedchecks of the temperature sensors during a given wash cycle. That is thecontroller 166 may be configured to repeat the steps of receiving thefirst temperature and the second temperature from the first temperaturesensor and the second temperature sensor, determining the temperaturechange of the first temperature sensor and the second temperaturesensor, comparing the temperature change of the first temperature sensorand the second temperature sensor, and determining if either of thefirst temperature sensor or the second temperature sensor ismalfunctioning throughout the wash cycle. Thus, method 300 may beunderstood to be an iterative process.

FIG. 5 depicts steps performed in a particular order for purposes ofillustration and discussion. Those of ordinary skill in the art, usingthe disclosures provided herein, will understand that the steps of anyof the methods discussed herein can be adapted, rearranged, expanded,omitted, or modified in various ways without deviating from the scope ofthe present disclosure. Moreover, although aspects of method 300 areexplained using washing machine appliance 100 as an example, it shouldbe appreciated that these methods may be applied to the operation of anysuitable washing machine appliance.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A laundry appliance comprising: a cabinet; a tubwithin the cabinet; a drum rotatably mounted within the tub and defininga chamber; an exhaust in fluid communication with the chamber; a firsttemperature sensor; a second temperature sensor; a controller operablycoupled to the first temperature sensor and the second temperaturesensor, the controller being configured to: execute a wash cycle;receive a first temperature from the first temperature sensor; receive afirst temperature from the second temperature sensor; receive a secondtemperature from the first temperature sensor; receive a secondtemperature from the second temperature sensor; determine thetemperature change of the first temperature sensor and the secondtemperature sensor based at least in part on the first temperature andthe second temperature of the first temperature sensor and the secondtemperature sensor; compare the temperature change of the firsttemperature sensor to the temperature change of the second temperaturesensor; determine if either of the first temperature sensor or thesecond temperature sensor are malfunctioning based on the comparison. 2.The laundry appliance of claim 1, wherein the controller is furtherconfigured to provide a notification to the user if it is determinedthat either of the first temperature sensor or the second temperaturesensor are malfunctioning.
 3. The laundry appliance of claim 1, whereinthe first temperature sensor is disposed in the tub.
 4. The laundryappliance of claim 3, wherein the first temperature sensor measures awater temperature.
 5. The laundry appliance of claim 1, wherein thesecond temperature sensor is disposed in the exhaust.
 6. The laundryappliance of claim 5, wherein the second temperature sensor measures anair temperature.
 7. The laundry appliance of claim 6, wherein the secondtemperature sensor is part of a humidity sensor.
 8. The laundryappliance of claim 1, wherein the temperature change of the firsttemperature sensor and the second temperature sensor is an averagechange of temperature of the first temperature sensor and the secondtemperature sensor based on a plurality of temperature readings of thefirst temperature sensor and the second temperature sensor.
 9. Thelaundry appliance of claim 8, wherein comparing the temperature changeof the first temperature sensor and the second temperature sensorfurther includes comparing the average change of temperature of thefirst temperature sensor and the second temperature sensor.
 10. Thelaundry appliance of claim 1, wherein determining if either of the firsttemperature sensor or the second temperature sensor are malfunctioningfurther includes determining whether the temperature change of the firsttemperature sensor is consistent with the temperature change of thesecond temperature sensor.
 11. The laundry appliance of claim 10,wherein the temperature change of the first temperature sensor isconsistent with the temperature change of the second temperature sensorif the temperature change of the first temperature sensor and the secondtemperature sensor both increase, decrease, or remain the same.
 12. Thelaundry appliance of claim 10, wherein the temperature change of thefirst temperature sensor is not consistent with the temperature changeof the second temperature sensor if the temperature change of one of thefirst temperature sensor or the second temperature sensor has atemperature change and the other does not.
 13. The laundry appliance ofclaim 1, wherein the wash cycle continues if it is determined that thefirst temperature sensor and the second temperature sensor are notmalfunctioning.
 14. The laundry appliance of claim 13, wherein thecontroller is further configured to repeat the steps of receiving thefirst temperature and the second temperature from the first temperaturesensor and the second temperature sensor, determining the temperaturechange of the first temperature sensor and the second temperaturesensor, comparing the temperature change of the first temperature sensorand the second temperature sensor, and determining if either of thefirst temperature sensor or the second temperature sensor ismalfunctioning throughout the wash cycle.
 15. A method for monitoringfor temperature sensor malfunctions in a laundry appliance having acabinet, a tub within the cabinet, a drum rotatably mounted within thetub and defining a chamber, an exhaust in fluid communication with thechamber, a first temperature sensor in the tub for measuring watertemperature, and a second temperature sensor in a humidity sensordisposed in the exhaust for measuring air temperature, the methodcomprising: executing a wash cycle; receiving a first temperature fromthe first temperature sensor; receiving a first temperature from thesecond temperature sensor; receiving a second temperature from the firsttemperature sensor; receiving a second temperature from the secondtemperature sensor; determining the temperature change of the firsttemperature sensor and the second temperature sensor based at least inpart on the first temperature and the second temperature of the firsttemperature sensor and the second temperature sensor; comparing thetemperature change of the first temperature sensor to the temperaturechange of the second temperature sensor; determining if either of thefirst temperature sensor or the second temperature sensor aremalfunctioning based on the comparison.
 16. The method of claim 15,wherein the method further comprises providing a notification to theuser if it is determined that either of the first temperature sensor orthe second temperature sensor are malfunctioning.
 17. The method ofclaim 15, wherein the temperature change of the first temperature sensorand the second temperature sensor is an average change of temperature ofthe first temperature sensor and the second temperature sensor based ona plurality of temperature readings of the first temperature sensor andthe second temperature sensor.
 18. The method of claim 17, whereincomparing the temperature change of the first temperature sensor and thesecond temperature sensor further includes comparing the average changeof temperature of the first temperature sensor and the secondtemperature sensor.
 19. The method of claim 15, wherein determining ifeither of the first temperature sensor or the second temperature sensorare malfunctioning further includes determining the temperature changeof the first temperature sensor is consistent with the temperaturechange of the second temperature sensor.
 20. The method of claim 19,wherein the temperature change of the first temperature sensor is notconsistent with the temperature change of the second temperature sensorif the temperature change of one of the first temperature sensor or thesecond temperature sensor has a temperature change, and the other doesnot.